Questions

Question 1

Answer 1

Empirical- Use thermometers, readings can depend on materials used, use ideal gas scale, requires very dilute gas.
Thermodynamic- Have a reference temp, T1 then any other temp T2 can be determined by running a reversible heat engine between them and comparing the heat exchanged at the two temperatures: T2 = T1 * (Q2/Q1)

Question 2

Question 3

Answer 3

n=pV/(RT)~0.5 moles
Heat capacity estimated to be Cv ~5R/2n
Delta T = 180K (estimated temperature drop from 200 to 20 degC)
Qh = nCvdelta T –> Remeber Cv and Cp are molar heat capacities (per mole- need to multiply by n to get heat capacity)
Qh = 0.5 * 5R/2 * 180 ~ 1870 J
W = Qh * Delta T/473 ~ 700 W

Question 4

Answer 4

Draw the diagram, expalain that if reversible heat engine is more efficient that a Carnot engine, heat would be moved from a lower temperature to a higher temperature, violating 2nd law. Does not matter which way you draw, could have done Carnot efficiency>efficienct other. Net effect, more heat moved from hot to cold violating clausius/2nd law as shown in the image.

Question 5

Answer 5